That stinks about your glass. Way to ruin a ride home.
If you are looking for date coded, makes finding more complex. I got mine from ECS. There are mixed reviews of various vendor quality and ECS seemed to have the best reputation. Looks distortion free to me, which was the primary complaint I saw.
I am not positive about the gasket. I know on my convertible you could save it, since there is the lock strip. Since you are trashing your old glass, then you may be in luck. Assuming there is not an abundance of sealer from previous install. You dont need sealer, but many use urethane as extra insurance.
You may want to pick up a set of trim clips to have on hand if they get damaged on removal. Sadly, you could have purchased at the show....